Satellite radio operators having been providing digital quality radio broadcast services covering the entire continental United States. These services offer approximately 100 channels, of which nearly 50 channels in a typical configuration will provide music with the remaining stations offering news, sports, talk and data channels. Digital radio may also be available in the near future from conventional analog radio broadcasters that will provide a terrestrial based system using signals co-located in the AM and FM bands.
Satellite radio has improved terrestrial radio's potential by offering a better audio quality, greater coverage and fewer commercials. Accordingly, in October of 1997, the Federal Communications Commission (FCC) granted two national satellite radio broadcast licenses. The FCC allocated 25 megahertz (MHZ) of the electro-magnetic spectrum for satellite digital broadcasting, 12.5 MHz of which are owned by Sirius Satellite Radio and 12.5 MHz of which are owned by the assignee of the present application “XM Satellite Radio Inc.”
The system plan for each licensee presently includes transmission of substantially the same program content from two or more geosynchronous or geostationary satellites to both mobile and fixed receivers on the ground. In urban canyons and other high population density areas with limited line-of-sight (LOS) satellite coverage, terrestrial repeaters broadcast the same program content for improving coverage reliability. Some mobile receivers are capable of simultaneously receiving signals from two satellites and one terrestrial repeater for combined spatial, frequency and time diversity, which provides significant mitigation of multipath interference and addresses reception issues associated with blockage of the satellite signals.
In accordance with XM Satellite Radio's unique scheme, the 12.5 MHZ band will be split into 6 slots. Four slots will be used for satellite transmission. The remaining two slots will be used for terrestrial reinforcement.
In accordance with the XM frequency plan, each of two geostationary satellites transmits identical or at least similar program content. The signals transmitted with QPSK modulation from each satellite (hereinafter satellite 1 and satellite 2). For reliable reception, the LOS signals transmitted from satellite 1 are received, reformatted to Multi-Carrier Modulation (MCM) and rebroadcast by terrestrial repeaters. The assigned 12.5 MHZ bandwidth (hereinafter the “XM” band) is partitioned into two equal ensembles or program groups A and B. Each ensemble will be transmitted by each satellite on a separate radio frequency (RF) carrier. Each RF carrier supports up to 50 channels of music or data in Time Division Multiplex (TDM) format.
Current user interfaces for internet radio broadcasts such as RealPlayer by Real Networks or Windows Media Player by Microsoft typically display information for an internet radio station for a single channel received via the internet and typically require a download. These are not live feeds and use up extensive resources on a CPU of a personal computer. These media players and other software such as vTuner by vTuner.com may sometimes index programming scheduled on different internet radio stations and also allow viewing of “current” programming. To actually listen to such “current” programming requires a connection to a website having the programming, as well as downloading and buffering of the programming. In other words, a URL link needs to be provided that enables a user's computer to connect to a remote server. For example, both Windows Media Player and vTuner have similar options called “Now Playing” or “On Now” where links are provided to various Internet radio stations that have scheduled programming. The granularity of the information provided when requesting a “Now Playing” or “On Now” may not necessarily provide detail to the extent of author or artist, music title and other desired information. Furthermore, the information provided may not be updated frequently enough to account for unscheduled programming changes.
Thus, in a digital audio radio system such as a satellite digital audio radio system or a terrestrial digital audio radio system, a need exists for a system that enables a user to display multiple channels and intelligently select desired content among the many channels in a flexible and user customizable manner using a user interface that overcomes many of the detriments described above.